Field of the Invention
The invention relates to a device for changing the jet shape of free-flowing products, in particular of foodstuffs, comprising: An inflow area for the free-flowing products to enter, an outflow area for the free-flowing products to exit, and several channels through which to pass the free-flowing products, wherein each channel comprises an inlet allocated to the inflow area and an outlet allocated to the outflow area, wherein each inlet of a channel has a first cross sectional area, and wherein each outlet of a channel has a second cross sectional area.
The invention also relates to the use of such a device for filling foodstuffs, in particular for aseptically filling foodstuffs.
Description of Related Art
Known in the area of packaging technology are numerous ways of filling free-flowing products into the packagings provided for this purpose. For example, the free-flowing products can be foodstuffs like milk, fruit juice, sauces or yogurt. Composite packagings with layers made of cardboard and plastic can be used as the packagings, for example.
One important step in filling the packagings has to do with filling the free-flowing products into the packagings as quickly as possible, so that a fast rhythm, and hence high numbers, can be achieved. However, filling is to take place largely without splashing and frothing despite the high flow rate, so that the hygiene requirements can be met, and to prevent the packaging or filling machine from becoming contaminated.
Especially stringent hygiene requirements are encountered for foodstuffs that are filled under sterile, i.e., germfree, conditions.
The stringent requirements can only be satisfied by adjusting the filling process to individual factors, for example the properties of the product to be filled and the volume and shape of the packaging. The adjustment routinely involves setting the flow volume and flow rate. In addition, the filling nozzle is often tailored to the product to be filled and the packaging, and changed out as needed. The filling nozzle largely determines the shape and speed profile of the filling jet. In addition, the filling nozzle is responsible for a drip-free filling. To this end, the volume flow is divided into several partial flows before exiting the filling nozzle, which are guided through individual channels. The advantage to this is that the product to be filled comes into contact with a larger wall surface, so that the residual quantity of product to be filled is reliably held in the channels if filling is interrupted, and does not drip uncontrollably onto the packaging or filling machine (“capillary effect”).
A filling nozzle for filling foodstuffs is known from EP 2 078 678 A1, for example. The filling nozzle shown therein comprises a replaceable plate with numerous holes for dividing up the volume flow. The holes are cylindrically shaped, and run parallel to each other so as to generate an especially straight filling jet with the plate (“flow straightening plate”). While the inlets of the holes lie in a plane, the outlets of the holes are situated on a curved surface, so that the holes vary in length viewed in the direction of flow. Varying the length of the holes is intended to influence the flow rate. In particular, the flow rate in the middle of the filling jet is to be decelerated more strongly by longer holes and the resultant higher friction than in the edge areas of the filling jet.
The filling nozzle known from EP 2 078 678 A1 has several disadvantages. First, the two-part construction makes it necessary to seal the plate away from the body of the filling nozzle. Residual product can become deposited in the gap between the plate and body to be sealed, which poses hygiene problems. Another disadvantage lies in the varying length of the holes. This is because a curved outflow area of the plate causes the partial flows of the product to be filled to detach from the underside of the plate at different times, and additionally exposes them to a varying drop height to the floor of the packaging. Those partial flows that are guided through shorter holes and detach from the underside of the plate sooner experience a gravitational acceleration earlier than those partial flows that are still in the longer holes at this point in time.
The varying drop heights cause the partial flows to accelerate for different times during freefall, and to accelerate at different increments. As a consequence, the velocity profile that arises on the underside of the plate is again altered during freefall. As a result, the velocity profile of crucial importance with respect to splashing as the filling jet impacts the bottom of the packaging can only be set very imprecisely with the proposed solution.
Therefore, an object of the invention is to configure and further develop the device described above in greater detail in such a way that the shape and velocity profile of the filling jet can be easily set.